Former Tropical Storm Cempaka strengthened to a typhoon southwest of Hong Kong on Monday. At 5:00 p.m. EDT on Monday the center of Typhoon Cempaka was located at latitude 21.3°N and longitude 112.4°E which put it about 130 miles (210 km) southwest of Hong Kong. Cempaka was moving toward the west-northwest at 3 m.p.h. (5 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 978 mb.
The small circulation around former Tropical Storm Cempaka strengthened quickly on Monday. A small circular eye formed at the center of Typhoon Cempaka. The eye was surrounded by a ring of strong thunderstorms. Bands of showers and thunderstorms were revolving around the core of Cempaka. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 20 miles (30 km) from the center of Cempaka. Winds to tropical storm force extended out 40 miles (65 km) from the center of circulation.
Typhoon Cempaka will move through an environment favorable for intensification during the next 12 hours. Cempaka will move over water where the Sea Surface Temperatures are near 30°C. It will remain under an upper level ridge over the South China Sea. The winds are weak in the ridge and there will be little vertical wind shear. Typhoon Cempaka could intensify during the next 12 hours.
Typhoon Cempaka will move south of a surface high pressure system over eastern China. The high pressure system will steer Cempaka slowly toward the west-northwest during the next 36 hours. On its anticipated track Tropical Storm Cempaka could approach the south coast of China near Yangjiang in about 12 hours. Cempaka will bring strong winds and heavy rain to the coast of Guangdong province. Since Cempaka will move very slowly some locations could receive extremely heavy rainfall and flash floods are likely in those places. Typhoon Cempaka could also produce of storm surge of up to 7 feet (2 meters) along parts of the coast where the wind blows the water toward the shore.
Elsewhere over the Western North Pacific Ocean, Tropical Storm In-Fa stalled southeast of Okinawa. At 5:00 p.m. EDT on Monday the center of Tropical Storm In-Fa was located at latitude 24.3°N and longitude 130.9°E which put it about 265 miles (425 km) southeast of Okinawa. In-Fa was moving toward the west-northwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 983 mb. Tropical Storm In-Fa is forecast to move toward the west during the next several days and to intensify to a typhoon. In-Fa could be south of Okinawa in 30 hours. It could be over the southwestern Ryukyu Islands in 72 hours and near northern Taiwan in less than four days.